Carburetor



Patented Aug. 16, 1938 UNITED STATES anim PATENT MG'QE Application July9, 1936, Serial In Sweden July 10, 1935 14 Claims.

The present invention relates to carburetors for internal combustionengines or motors of the type in which the fuel, preferably of a highboil- V ing point is mechanically sub-divided and vapourized in avapourizing chamber located within the exhaust pipe and thereupon mixedwith air and sucked away through the fuel inlet pipe of the engine.

Such internal combustion engines as use a fuel having` a high boilingpoint (as kerosene) usually are started with the aid of a more volatileoil (as gasoline). In such class of bi-fuel motors two carburetors areusually provided, one for crude oil the other for petroleum.

In such carburetors it has been found that the vapourizing chamber dueto poor combustion and deposits of carbon will not work satisfactorily.

In order to remove such deficiencies according to the present inventionthe vapourizing chamber of the kerosene carburetors is of suchconstruction and provided with means for having it swept free ofremaining fue] gases and carbon residue during its idle period when theengine is driven by gasoline.

Another object of the invention is to provide means whereby the parts ofthe vapourizing chamber are heated also from the inside during its idleperiod. p

Still another object is to use a material for the construction of theVapourizing chamber which has a high coefficient of expansion thusenabling deposits of carbon etc. to be more easily removed.

The present invention will be clearly set forth in the followingdescription referring to an in 35i ternal combustion motor having twocarburetors of which only the kerosene carburetor is described and shownin the drawing. It will be understood, however, that the carburetor asdescribed is given as'an example only.

In the accompanying drawing:

Fig. 1 is a sectional elevation of a carburetor constructed according toone example of carrying the invention into effect.

Fig. 2 is a partial sectional elevation of the 5 kerosene vapourizingchamber in a non-working state as it is heated by the exhaust or refusegases when the motor is driven by gasoline fed to the gasolinecarburetor.

Fig. 3 is an enlarged fragmentary View in sec- ;0. tion showing certaindetails of construction providing for the entrance of the exhaust gasesto the vaporizing chamber when the valve is closed.

In Fig. l I is a length of tubing having flanges at both ends to providefor its securing to the iexhaust pipe of which. it is intended to form apart. Thus the hot exhaust gases will pass therethrough heating thevapourizing chamber 2 located therein. The vapourizing chamber consistsof a substantially cylindrical hollow casting having at its upper end acylindrical 5 opening 3 leading to the hollow interior or bore of thevapourizing chamber 2. Said bore preferably is of a slightly conicalshape tapering upwards. The wall of the vapourizing chamber 2 at itslower edge forms a valve seat 6. Where 10 the opening 3 merges into thevapourizing chamber a groove 4 is formed into the wall of said chamber.Into said groove l three passages 5 open spaced apart at the samedistance around the periphery of the only being shown in the drawing. Ahollow conical valve 'l is provided for closing the aperture at thelower end of the vapourizing chamber by being pressed against the valveseat At the top of the hollow valve 'l is an annular member 20 8 whichat its upper part is of a cylindrical shape whereas its lower part isconical tapering upwards. On the face of said annular member 8 arerecesses or grooves 3a. and the cylindrical portion of the annularmember is surrounded by 25 an annular valve 9 which is made to closeagainst a seat on the vapourizing chamber wall as shown. The annularvalve 9 when closed together with the annular groove Il forms a passagecommunicating through an annular slot if) with v the recesses as grooves8a in the member 8. Above the member 8 a thin annular collar ll isprovided which at its face has recesses or grooves lla corresponding innumber to those of the annular member 8 but which width. A hollow stemi2 is passed through said member 8 and collar l i and threaded into theconical valve l, and the top of said stem l2 forms part of aclaw-coupling and a little below this portion four guiding arms forminga cross are provided. Below said cross are four passages l 5 openinginto the bore of the stem I2 or the hollow of the valve 'l so as toenable the gases to pass therethrough. From the vapourizing chamber (atthe right in Fig. l) a passage I6 of a comparatively great width isprovided through which the vapourizing fuel` passes to the mixingchamber Vl. In order to secure a gastight fitting between thevapourizing chamber and the mixing chamber and to locate the vapourizingchamber properly a short length of a steel tube HS has been driven intothe wall of the exhaust tube l, said tube i3 having a conical portion tobe fitted into the passage i6.

The conical configuration of the inner faces groove, one such passage 15of the vapourizing chamber which are also highly polished has the effectthat the cokelike residue forming on the walls by decomposition of thefuel will be easily removable. Preferably also the vapourizing chamberis made from a material having a high Coeicient of expansion whichgreatly augments the said effect. For this reason, however, it isimpossible to have the vapourizing chamber xedly positioned within theexhaust tube. As shown on the drawing a resilient fastening means I9 isprovided which tends to press the vapourizing chamber both against theconical portion of the tube I8 and against a second tube Z having at oneend a ball-shaped portion and being spherical at its other end, saidtube 20 having a passage 23a therein through which the fuel isintroduced. Said tube allows the vapourizing chamber to move withoutcausing leaking at the joints. At the lower end of the conical valve 1guiding means 2I are provided. At the top a lifting stem 22 is providedconnected through the claw-coupling I3 with the stem I2. On each side ofthe eX- haust tube I there is an opening which can be closed by ashutter and through which the vapourizing tube may easily be taken outfor inspection and adjustment.

In a cut-out portion of the lifting stem 22 a lever 23 is entered whichlever is xed to a shaft 2.

Referring to Fig. 1, above the mixing chamber I1 the fuel valve chamber25 is situated. It encloses the valve stem 26 which at its lower end isconical and forms a valve or needle. Below said needle we see the nozzle21 which has a calibred opening and a valve seat 28, which conforms withthe conical valve portion of the stem 26. The bore of a nipple threadedinto the valve chamber 25 communicates with the bore of the nozzle andleads the fuel thereto from a vacuum tank, a floating chamber or aregulating valve.

In the valve housing 25 an adjustable air passage 29 and also a passage30 are provided, said passage 39 communicating with the vapourizingchamber through the pipe 29 and the passages 5. The valve stem on itsperiphery 26 has a groove 3l of such a shape that when the valve is openthe air duct 29 communicates through said groove 3| with the passage 3U.However, when the stem 26 moves downwards, its needle coming to restagainst its seat 28 a cylindrical portion of the stem 26 will close thepassage 29 and shut olf the supply of air entering therethrough.

The passage I6 through the pipe I8 communicates with the pipe 32 beingpart of the mixing chamber I1. The pipe I1 can be shut by a throttle 33.A branch pipe of the mixing chamber I1 which opens into the air canlikewise be closed by a throttle 34. Levers 38 and 39 are fastened tothe throttles 33 and 34 respectively and are interconnected by a rod 40in such a way that the gas-throttle 33 is fully opened when thegasthrottle 34 is only half-opened and remains in said position untilthe gas-throttle has been fully opened. This may be accomplished byproviding springs (not shown) on the shaft 33a of the valve 33 and shaft34a of valve 34 arranged respectively to retain said valve 33 in theposition shown and tending to close said valve 34 so that when the rod40 is moved downwardly, for example, the valve 33 will move togetherwith its lever 38 and when said valve has been closed the lever 39 beingmuch longer than lever 38 will not have moved a distance sufficient toclose valve 34 which may be closed only by moving the rod 40 stillfurther downward, the lever 38 being mounted with respect to valve 33 sothat it will be free to follow this further movement of said rod 49.This control of the valves 33 and 34 forms no part of the inventionhowever and may be accomplished by various types of control mechanisms.

In the chamber I1 in front of the pipe 32 an annular sliding member 35that is conical in crosssection and can be moved towards and away fromthe end of the pipe 32 thus restricting or widening the annular space 31between said end of the pipe 32 and the annular member 35, therewithproviding a means for regulating the quantity of air admitted when theair throttle 34 is fully opened. The pipe 36 is adapted to be secured tothe gas inlet pipe of the engine.

The shaft 24, the means for lifting the valve stem 26 and the shaft onwhich the throttle 34 is mounted all are connected to means regulatingthe velocity of the motor-as the gas pedal-in the usual way known in theart.

In use the vapourizer works as follows:

The engine is started on the gasoline vapourizer (not shown) in theusual way. The valve 26 and the air throttle 34 (and consequently thegas throttle 33) are shut. The movable parts of the vaporizing chamberare in the position shown in Fig. 2, viz. the valve 1 is lowered. Aquantity of the hot exhaust gases now will pass through the vaporizingchamber heating it also from the inside. After the engine has beenworked in this way for some minutes it is possible to change over tokerosene. When the contraption is applied to automobiles doublegas-pedals may be used, one

for the gasoline vapourizer and the other for the f' kerosenevapourizer; the operator effecting the change only by moving his footfrom one pedal to the other. When the pedal of the gasoline vapourizeris released the air throttle pertaining thereto is shut. As the operatorpresses upon the kerosene pedal the valve 1 is first lifted so that itis pressed against its seat 6 and the annular member 9 will also t itsseat 4.

Then the oil regulating valve 26 and the air throttle 34 are opened inconformity with the dcpressing of the pedal, viz according to the powerrequired. The throttle 33 is not used as a regulating means but servesonly to shut off the exhaust gases from the inlet pipes of the cylinderswhen the engine is worked by gasoline. This is the reason for thespecial connection between this throttle and the air throttle 34. Thethrottle 33 should be opened speedily.

In the inlet pipe of gas mixture to the engine and therefore also in thevapourizing chamber there reigns a pressure below air-pressure. The fuelis sucked through the nozzle 21 and mixed with a small quantity of airentering through the passage 29, then passes through the ducts 30 and20, is distributed and passes through each of the three separate ductsand enters the annular groove 4 from different directions and passesthrough the annular space I0 and the grooves Ba in the member 8 wherethe mixture is met at an angle of 90 by a small quantity of very hotexhaust gases entering through the grooves IIa in the member I I. Owingto the low pressure in the vapourizing chamber and the high pressure Inthe exhaust pipe these gases attain a very great velocity so that thefuel is brought into a state of very fine sub-division. The mixture nowpasses along the grooves 8a in the member 8 inside of the member 9 andis expelled from the conical portion thereof against the hot walls ofthe vapourizer and is wholly vapourized. Part of the exhaust gases theinterior of passes through the openings I5 and the valve 'I and preventsits cooling down. The vapourized fuel passes through the duct I6 and thepipe 32 whereupon it is mixed with air entering through the throttle 3dwhich at` 35 passes at great velocity around the mixture of fuel vapourand transports it through the intake pipe of the engine. Thereby thefuel vapour is cooled and enters the cylinders in a fog-like stateadapted for the burning.

Always when the gas pedal is relievedthus also when the car is allowedto roll along under action of its` inherent kinetic force-the fuel isshut olf through the lowering of the stem` 26 so that the valveisclosed-upon its seat 2B and also the air passage 29 is shut 01T.Simultaneously throttles 33 and 34 are closed. Thereupon the valve 'l islowered and brought into the position shown in Fig. 2. The exhaust gasesnow are free to sweep through the vapourizing chamber and liberate itfrom remaining fuel gas and residues. This is very important asotherwise the remaining fuel gas at the next opening of the throttleswould enter the engine as a surplus and therefore cause insufficientburning and smoking.

When idle the engine runs on gasoline fuel provided by the idle runnozzle and the change will be automatically effected as soon as thethrottles 33 and 34 are shut causing a lower pressure to arise in theinlet pipe.

The vapourizing chamber that is the object of the present invention hasbeen described as applied to a special form of carbuetor but it is clearthat it may be used for other carburetors also and I do not wish torestrict my invention to any special type of carburetors or to any formof execution.

Having thus described my invention what I claim to protect is:

l. In a bi-fuel device of the character described comprising an exhaustchamber, a vapourizing chamber for heavy fuel located in said exhaustchamber, a valve controlled opening in said vapourizing chamber for theintroduction of exhaust gases thereto from the exhaust chamber, and avalve controlled outlet opening in the Vapourizing chamber for returningsaid exhaust gases from the latter to said exhaust chamber.

2. In a bi-fuel device of the character described comprising an exhaustchamber, a vapourizing chamber for heavy fuel located in said exhaustchamber, said vapourizing chamber having an inlet opening therein forthe introduction of exhaust gases thereto and an outlet opening forreturning said exhaust gases to the exhaust chamber, and valve means forcontrolling the passage of the exhaust gases through said openings inthe vapourizing chamber.

3. In a bi-fuel device of the character described comprising an exhaustchamber, a vapourizing chamber for heavy fuel located in said exhaustchamber, said vapourizing chamber having an inlet opening therein forthe introduction of exhaust gases thereto and an outlet opening forreturning said exhaust gases to the exhaust chamber, and a single valveelement for controlling passage of the exhaust gases through saidopenings in the vapourizing chamber and operable to simultaneously closethe openings.

4. A device as claimed in claim 1 wherein the inner configuration of thevapourizing chamber is substantially conical.

5. A device as claimed in claim 3 wherein the external configuration ofthe valve element is substantially conical.

6. A device as claimed in claim 3 wherein the inner configuration of thevapourizing chamber and the externalconfguration of the Valve elementare substantially conical. Y l

7. A deviceas claimed in claim l wherein the vapourizing chamber iscomposed of material possessing a high coefficient of expansion..

8. In a bi-fuel device of the character-described, an exhaust chamber, avapourizing chamber in said exhaust chamber having inletl and outletopenings therein for the ingress and egress of exhaust gases, and avalve element operable to open and close said openings in saidrVapourizing chamber, the portion of said valve element cooperable withthe inlet opening; being constructed and arranged with respect theretoso that the quantity of exhaust gases entering the vapourizing chamberare controlled by the relative position of the valve with respect to theopening.

9. In a bi-fuel device of the character described, an exhaust chamber, avapourizing chamber having inlet and outlet openings therein for theingress and egress of exhaust gases, and a valve element operable toopen and close said openings in said vapourizing chamber, the portionsof said valve element cooperable with the openings to close the samebeing constructed and arranged with respect to each thereof so thatpassage through said openings is controlled by the relative position ofthe valve with respect thereto.

returning said exhaust gases to the exhaust chamber, valve means forcontrolling the passage of valve means for actuating the same.

1l. In a bi-fuel device of the character described, an exhaust chamber,a vapouiizing structed and arranged with respect to each thereof so thatpassage through said openings is controlled by the relative position ofthe Valve with respect thereto, and means operatively connected to saidvalve means for actuating the same.

12. In a bi-fuel device of the character described, an exhaust chamber,a vapourizing chamber for heavy fuel located in said exhaust chamber,said vapourizing chamber having an inlet opening therein for theintroduction of exhaust gases thereto and an outlet opening forreturning said exhaust gases to the exhaust chamber, a of the ex whensaid inlet opening thereto is closed by the valve element.

13. In a bi-fuel device of the character described, an exhaust chamber,a vapourizing chamber for heavy fuel located in said exhaust chamber,said vapourizin-g chamber having an inlet opening therein for theintroduction of exhaust gases thereto and an outlet opening forreturning said exhaust gases to the exhaust chamber, a valve element forcontrolling passage of the exhaust gases through said openings in thevapourizing chamber and operable to close the openings, means forfeeding fuel to the vapourizing chamber through the inlet openingtherein, and means forming a part of said valve element constructed andarranged to permit the passage of fuel and exhaust gases to saidvapourizing chamber when said inlet opening thereto is closed by thevalve element.

14. In a bi-fuel device of the character described comprising an exhaustchamber, a vapourizing chamber for heavy fuel located in said exhaustchamber, said vapourizing chamber having an inlet opening therein forthe introduction of exhaust gases thereto and an outlet opening forreturning said exhaust gases to the exhaust chamber, valve means havinga bore extending axially therethrough operative to control the passageof the exhaust gases through said openings in the vapourizing chamber,and means forming a part of said valve means constructed and arranged sothat a portion of said exhaust gases pass through the bore in the valvemeans.

SVEN EMANUE'Lv BENGTSON.

